High-intensity interval training significantly improved maximal oxygen uptake (VO2max) by SMD 1.20 (95% CI 0.86–1.54) compared to controls in middle-aged and older women, but showed limited effects on muscle strength and physical function.
Systematic Review (n=646)
Does high-intensity interval training (HIIT) improve cardiorespiratory fitness and physical function in middle-aged and older women?
HIIT significantly improves maximal oxygen uptake in middle-aged and older women but is insufficient as a standalone intervention to meaningfully improve muscle strength or functional mobility.
Estimación del efecto: SMD 1.20 for VO2max improvement (95% CI 95% CI 0.86 to 1.54)
valor p: p=<0.01
Background To systematically evaluate the effects of high-intensity interval training (HIIT) on cardiorespiratory fitness and physical function in middle-aged and older women. Methods PubMed, Web of Science, and Scopus were searched from inception to November 2025. Randomized controlled trials comparing HIIT with control interventions in middle-aged and older women were included. Random-effects meta-analyses were performed. Primary outcomes were maximal or peak oxygen uptake (VO 2max /VO 2peak ) and physical or functional performance measures. Results Nineteen randomized controlled trials were included. Meta-analysis showed that HIIT significantly improved VO 2max compared with control interventions (SMD = 1.20, 95% CI 0.86–1.54, I 2 = 31%), with high certainty of evidence. No significant effect was observed for VO 2peak (SMD = 0.23, 95% CI −0.23 to 0.69). HIIT did not significantly improve muscle strength (SMD = −0.17, 95% CI −1.04 to 0.70), though strength assessments were not always specific to the muscle groups trained, flexibility, or sit-to-stand performance. Walking ability showed a borderline significant improvement (SMD = 0.49, 95% CI 0.00–0.97), with very low certainty of evidence. Subgroup analyses indicated consistent VO 2max improvements across age groups, body mass status, and intervention durations. Conclusion HIIT significantly improves cardiorespiratory fitness in middle-aged and older women but shows limited effects on physical function. HIIT alone is insufficient to comprehensively improve functional performance. Systematic Review registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420251272861 .
Cai et al. (Wed,) conducted a systematic review in Middle-aged and older women (aged 44–81 years), including peri- and postmenopausal women, some overweight, obese, or with cardiometabolic risk factors (n=646). High-intensity interval training (HIIT) vs. Non-exercise control, usual care, moderate-intensity continuous training, resistance training, or combined exercise interventions was evaluated on Maximal oxygen uptake (VO2max) and physical or functional performance measures (e.g., 6-min walk test, Timed Up and Go, sit-to-stand) (SMD 1.20 for VO2max improvement, 95% CI 95% CI 0.86 to 1.54, p=<0.01). High-intensity interval training significantly improved maximal oxygen uptake (VO2max) by SMD 1.20 (95% CI 0.86–1.54) compared to controls in middle-aged and older women, but showed limited effects on muscle strength and physical function.